Ore concentration



thate may be added to the ore Patented Aug. 13, 1935 UNITED STATES 01mCONCENTRATION Cornelius H. Keller, San Francisco, Calif., as-

signor to Minerals Separation NorthAmerican Corporation, New York,.N.Y., a corporation of Maryland No Drawing.

Serial No. 713,014. known This invention relates to the concentration ofores by flotation, and is herein illustrated as applied to theconcentration of metalliferous ores with the aid of activated carbons,such as activated charcoal, in the presence of a xanthate.

The expression activated carbon" as used in this specification isintended to refer to a vegetable wood charcoal .whose adsorptive andabsorptive property has been augmented by chemicaland/or physical means.

This application is a continuation in part of my application Serial No.

According to the present invention the xanadmixed with the activatedcarbon, or the activated carbon and xanthate may be added separately tothe agitated pulp and so brought into contact.

When the pulp containing the added xanthate and the activated carbon isagitated in the usual manner, a froth concentrate may be separated inthe usual way. The recovery of metalliferous mineral in a concentrateobtained in the presence of the activated carbon may not vary much fromrecovery of metallife'rous mineral in the absence of the carbon, but itis found that the concentrate obtained in the presence of the activatedcarbon is considerably richer in metalliferous mineral thanthe'concentrate obtained by the usual procedure with xanthate alone. Inother words, the activated carbon causes the procedure to exclude fromthe concentrate a large proportion of the gangue, or so-calledinsoluble, of the ore which the concentrate would otherwise carry.Sometimes, however, the concentrate carries also an increased proportionof the metalliferous mineral in the ore.

Concentrates carrying the minimum of gan'gue were obtained-when thexanthate added was in the neighborhood of a hundredth of a pound pertone of dry ore. In many cases the presence of activated carbon resultedin reducing the gangue content of the concentrate by about one-third. IOther features and advantages will hereinafter appear in connection withthe following exam-' pies:

Example 1.- 10 mesh Nevada Consolidated ore was wet ground for '7minuteswith 5 pounds of to calcium oxide per ton of ore, diluted withadded water and agitatedfor 2 minutes with 0.1 pound of pine oil, 1.0pound activated charcoal and 0.01 'pound of potassium ethyl xanthate,all per ton of ore. A froth concentrate was then separated for 5minutes.

pulp in solution Application February 26, 1934,

In Great Britain, date un- 4Claims. (Cl.-209166) The concentrate was4.2% of the weight of the heads. The heads contained 1 .39% copper, theconcentrates 30.88% copper and 9% insoluble or gangue, and thetailingscontained 0.10% copper, representing a recovery of 93.1% of thecopper. When no charcoal was used the concentrate contained only 27.04%of copper and 16% insoluble or gangue.

Example 2.-When 0.01 pound of potassium benzyl xanthate was substitutedfor the ethyl xanthate, using activated charcoal in an otherwiseparallel test, with heads containing 1.36%

copper, a concentrate weighing 4.23% of the heads was obtained. Theconcentrate contained 28.64% of copper and 18.6% insoluble or gangue,and the tailings contained 0.15% of copper,representing a recovery of89.4% of the copper. In

the absence of charcoal, other conditions being the same, theconcentrate assayed only 24.8% of copper and 21.0% insoluble or gangue,with a slightly higher recovery.

Example 3.-When cyclohexanyl xanthate at the rate of 0.01 pound pertonof ore was substituted for ethyl xanthate in a parallel test, usingactivated charcoal with heads containing 1.36% of copper, theconcentrates weighed 4.22% of the heads and contained 28.8% insoluble organgue. The tailings contained 0.15% of copper, representing a recoveryof 89.4% of the copper.

In the absence of the activated charcoal, a slightly higher recovery wasobtained with, however, a reduction of nearly 4% of copper in theconcentrates and an soluble or gangue.

Example 4.-When Nevada Consolidated copper ore was treated withactivated charcoal and potassium amyl xanthate added separately to thepulp and brought into contact by the strong agitation thereof, theprocedure and result were as follows:

The ore was wet ground in a ball mill withipounds of lime per ton, for'7 minutes, water added, and agitated for 2 minutes in a flotationmachine, with the addition of 1 pound activated charcoal, 0.01 poundpotassium amyl xanthate and 0.1 pound of pine oil, all per ton of' ore.A froth concentrate 'was then separated for 5 minutes. The headscontained 1.36% of copper, the concentrates weighed 3.54% of the headsand contained 27.04% of copper with 14.8% insoluble or gangue, and .thetailings contained 0.42% of copper, representing a recovery of 79.3% ofthe cop- A parallel test made without the use of acof copper and 14.4%

increase or 7.6% in inp the calculated assay tivated charcoal resultedin a concentrate assaying 25.6% of copper, containing 20% insoluble organgue.

Example 5.--When in a parallel test of the same Nevada Consolidatedcopper ore, potassium secgangue. The tailings contained 0.44% of copper,

representing a recovery of 70.0% of the copper.

A parallel test made without the use of activated charcoal resulted in aconcentrate assaying 21.76% of copper and containing 24.8% insoluble organgue.

The above tests were run Nuchai, activated charcoal. Ten mesh MountainCopper Company ore was reground 20 minutes with 3 pounds of lime perton, diluted with Water and agitated for 3 minutes with 5 lbs, Nuchar,0.1 pound potassium ethyl xanthate, and 0.2 pound of pine oil, all perton of ore. The froth was removed for a period of 5 minutes. Theconcentrates were 9.65% by weight of the heads. They assayed 26.24% ofcopper and 6.2% insoluble o1 gangue. The heads contained 2.98% copper bycalculation, and the tails assayed 0.5% copper. The copper recoveryamounted'to 93.4%of the total.

In a parallel test made with another activated carbon, so-called Norite,which is an activated carbon understood to be made from distillationresidue from paper mill waste liquors electrically carbonized andactivated by steam, the concentrates weighed 13.4% of the weight of theheads, of which was 2.93% copper. The concentrates assayed 18% copperand 3.8% insoluble or gangue, representing a recovery of 82.3% of thetotal copper in the ore.

A parallel test made on the same ore, but without activated charcoal,resulted in a concentrate weighing 24.4% of the heads, The calculatedcopper of the heads was 3.1%. The concentrates contained 11.52% copperand 28.4% insoluble, representing a recovery of 90.7% of the copper inthe ore.

Ten mesh Desloge Lead Company ore was reground 15 minutes diluted withwater and agitated 2 minutes with 4 pounds Nuchar, an

with so-called Elli activated carbon supposed to be made from gasactivated birchwood charcoal, 0.05 amyl Xanthate, and 0.15 pound-pineoil, all per ton of ore. The froth concentrate removed for -5 minutesrepresented 5% by weight of the heads, the calculated lead content ofwhich was 3.96%. The concentrates contained 77% lead and 2.1% insolubleor gangue, representing a lead recovery of 97.1%. The tails assayed0.12% lead.

A similar test made with Norite resulted in a concentrate weighing 6.3%of the heads, the calculated lead content of which was 4.35%.

The concentrates contained 68% lead and 3.4% insoluble or gangue,representing a lead recovery of 98.4%. The tails assayed 0.075% lead.

A parallel test made without activated charcoal produced concentratesassaying 64.8% lead and 3.3% insoluble or gangue. These represented 6.3%by weight of the heads, the calculated lead content of which was 4.19%.The lead recovery in the concentrates amounted to 95.7%.

1 The tails assayed 0.2% lead.

Ten mesh zinc ore, free from lead, and from the Joplin district, wasreground 10 minutes, diluted with water and agitated 2 minutes with 1.0pound CuSO4, 10 lbs. Nuchar", 0.3 pound poconcentrate containing 64.7%zinc and 2.6% insoluble or gangue. It weighed 18.6% of the heads, thecalculated zinc content of which was 14.09% zinc, representing zincrecovery of 85.5%. The tails assayed 2.5% zinc.

A parallel test without activated charcoal produced a concentrateweighing 21.1% of the heads.

' The calculated zinc content of the heads was 13.9% zinc. Theconcentrates contained 62.8% zinc and 5.4 insoluble or gangue,representing a recovery of 95.5% of the total zinc in the ore. The tailsassayed 0.8 zinc.

Having thus described certain embodiments of the invention, what I claimis:

1. The process of concentrating an ore, which consists in dispersingtogether in an ore pulp an alkaline xanthate and an activated carbonmaterial, agitating such pulp with another agent so as to produce a,floating concentrate, and separating the concentrate.

2. The process of concentrating an ore, which consists in dispersingtogether in an alkaline ore pulp an alkline xanthate and activatedcharcoal, agitating such pulp with another agent so as to produce afloating concentrate, and separating the concentrate.

3. The process of concentrating an ore, which consists in dispersing inan ore pulp separately mixed Xanthate solution and activated charcoal,

agitating the pulp with another agent so as to CORNELIUS H. KELLER.

